My DigitalZone

“Warning: Cannot modify header information – headers already sent by (output started at /some/path/public_html/xxxx.php:50) in /some/path/public_html/some_dir/yyyy.php on line 250″

If you have a PHP based web site, you may have encountered this Warning message. It’s frustrating when it happens. If you are a PHP guru, you may be able to solve it right away. For a newbie PHP programmer, it’s not obvious. I scratched my head when I first encountered this problem, and it took a long time to fix it.

First, you need to check the obvious. Have you edited the files in your warning message before you started to get the warning? You need to remove any white space before and after .

Then, you need to check to see if you are using header() before any output is sent. For example, the php.net gives some examples. Here’s another example.

My laptop wasn’t working well, so I restored the factory default settings. It’s working fine now, but I am now in search of my next one. I noticed that laptop prices have been going down dramatically. So, buying a new laptop is not too big of a deal these days. Still, I had to check out eBay to see what’s available there. Not bad. They have some nice ones there. Here are some listings for HP/Compaq.

US $61.05 (5 Bids) End Date: Saturday Jul-31-2010 18:21:06 PDT Bid now | Add to watch list

US $31.00 (4 Bids) End Date: Saturday Jul-31-2010 18:10:25 PDT Bid now | Add to watch list

US $15.50 (5 Bids) End Date: Saturday Jul-31-2010 15:32:32 PDT Bid now | Add to watch list

US $15.50 (5 Bids) End Date: Saturday Jul-31-2010 15:15:35 PDT Bid now | Add to watch list

US $15.50 (6 Bids) End Date: Saturday Jul-31-2010 14:32:38 PDT Bid now | Add to watch list

Have you ever accidentally deleted a photo from your digital camera before you had a chance to download it to your PC? I have. I looked for a recycle bin on my camera to see if I could recover from a recycle bin but there was no recycle bin on the SD card. Don’t despair! There are ways to recover deleted photos from a memory card. But most of them are not free. You need to shell out at least $20 to use the service/software. There is a free one, though. So, the option I recommend is to use PC Inspector Smart Recovery. I tried it and It worked fine. So, here are the steps you need to follow.

• Download PC Inspector Smart Recovery and install it.
• If your computer has a memory card slot, insert the memory card in it. If your PC doesn’t have the slot, connect the digital camera to the PC with a cable.
• Start the PC Inspector Smart Recovery.
• Select the drive to recover the photo(s). This is usually E: or F:.
• Select the folder on your computer where you want to store the recovered photo(s).
• Click “start,” then the program starts to scan the memory card. The result window will show all the pictures you ever deleted. You can pick the ones you want to recover.

Since the program scans the card sector by sector, it may take a long time to finish scanning. I did it for a 2 GB card, and it took about 2 hours to complete the scan. But it’s worth the wait.

As I had problems with VERY persistent trojans (see this post), I spent this weekend reinstalling Windows XP. It was tedious but went well except for 2 glitches. The computer didn’t recognize the network connection and audio devices. So, I had to download drivers from the ASUS sites. I didn’t have to do this when I first installed WinXP, but anyhow, everything is fine now.

Of course, I installed Virus protection and firewall program to protect it.

I spent half a day last weekend to help my friend to battle with a computer infected with trojans. Lots of them. They were persistent and difficult to remove. Malwares like AntiVirus 2008 or AntiVirus 2009 as described in this post were easier to remove compared with the ones I encountered last week. Basically, AntiVirus 2008 and AntiVirus 2009 are malware that uses scare tactics to make users to buy their own virus removal software. The ones I encountered at my friend’s house turned out to be a kind called “rootkit.”

According to wikipedia, “A rootkit is a software system that consists of a program, or combination of several programs, designed to hide or obscure the fact that a system has been compromised… An attacker may use a rootkit to replace vital system executables, which may then be used to hide processes and files the attacker has installed, along with the presence of the rootkit. Access to the hardware, e.g., the reset switch, is rarely required, as a rootkit is intended to seize control of the operating system.” This is a serious threat.

The computer in question has a good working McAfee Virus scan and its On Access scan window keeps popping up saying that trojan was found and deleted. That’s how my friend found about their existence. The reason he asked my help was that it looks like it was catching the same gourp of files again and again, even though the virus scan said it had deleted them. Some of the files were in windows\system32\drivers. They were systemntmi.sys, amd64si.sys, i386si.sys, amd64si.sys, and lots of others.

So, there I was. Trying various other software. I tried Malwarebytes’ Anti-Malware. It found a bunch of infections. Like over 50. It said it had removed them. Reboot. Scanned again. Strange. It found them again. Removed. Reboot. I used Avast! Reboot. I used Trend Micro Rootkit Buster. Reboot. As I said earlier, the trojans were persistent. I decided to take a break at that point to do more research on the issue.

What I will do this weekend is to do an OS reinstall this weekend. As the wikipedia article says, “Even if the nature and composition of a rootkit is known, the time and effort of a system administrator with the necessary skills or experience would be better spent re-installing the operating system from scratch.”

Oh well. I’m looking at two system restore projects within a week!